1. West China Second University Hospital, West China Women's and Children's Hospital; Department of Pediatrics; No. 17, Section Three, Ren Min Nan Lu Avenue Chengdu Sichuan China 610041
2. The First People's Hospital of Long Quan Yi District; Department of Paediatrics; 417 Oupeng Avenue Long Quan Yi District Chengdu Sichuan China 610100
3. The Fourth Hospital of Sichuan Province; Department of Paediatrics; 57, Chengshou Dongdajie Chengdu Sichuan China 610016
4. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese Evidence-Based Medicine Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041
5. West China Second University Hospital, West China Womens and Childrens Hospital; Department of Pediatrics; No. 17, Section Three, Ren Min Nan Lu Avenue Chengdu China 610041